Low-Frequency Broadband Absorbing Coatings Based on MOFs: Design, Fabrication, Microstructure and Properties

Abstract

Although most microwave absorbing materials (MAMs) have good absorption ability above 8 GHz, they perform poorly in the low-frequency range (1–8 GHz). Metal–organic frameworks (MOFs) derived carbon-based composites have been highly sought after in electromagnetic materials and functional devices, due to their high specific area, high porosity, high thermal stability, low reflection loss, and adjustable composition. In this review, we first introduce the three loss types of MAMs and argue that composite materials are effective ways to achieve broadband absorption. Secondly, the absorbing properties of traditional materials and MOF materials in the literature are compared, followed by a discussion of the promising strategies for designing MAMs with broadband absorption in low frequencies based on the recent progress. Finally, the main problems, fabrication methods, and applications are discussed for their future prospects.

Silver-Based Surface Plasmon Sensors: Fabrication and Applications

“…In the second type of composite, the use of silver nanomaterials and other materials conforming to the composition of a core-shell structure is the most popular type of composite for current applications, and the most important purpose of this type is to improve the sensitivity of SERS detection [ 155 , 156 , 157 ]. Chen et al [ 141 ] synthesized several layers of MoS 2 directly on silver nanoparticles by thermal decomposition, resulting in a MoS 2 /AgNPs hybrid system for surface-enhanced Raman scattering as shown in Figure 12 d. The nano-gap between the two metallic nanostructures has been shown to be effective in concentrating the incident electromagnetic field into a small space.…”

Effect of Blending of Shellac, Carbonyl Iron Powder, and Carbonyl Iron Powder/Carbon Nanotube Microcapsules on the Properties of Coatings

“…Electromagneticabsorption materials are prepared in microcapsules and applied to water-based coatings, which can prevent the harm of electromagnetic radiation to the human body and broaden the application range of water-based coatings on fiberboard surfaces. Among various traditional electromagnetic-absorption materials [24,25], magnetic metal materials have a high saturation magnetization and high magnetic permeability. This can achieve better impedance matching with air, thereby reducing coating thickness and increasing electromagnetic-absorption bandwidth.…”

A multi-layer core–shell structure CoFe2O4@Fe3C@NiO composite with high broadband electromagnetic wave-absorption performance

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